The programs UNC 32/33 read uncertainty information from cross-section libraries in the ENDF/B-V format (autocorrelations) and convert these uncertainty data to a group structure selected by the user. In the conversion procedure a weighting neutron spectrum is needed.
The converted cross-section uncertainty data can be used in adjustment programs and to calculate the uncertainty in calculated reaction rates.

The calculation time expressed in system seconds is problem dependent. For the program UNC32 about 20 s and for the program UNC33 about 60 s are needed for a relatively complicated reaction.
NEA 1139/01: NEA-DB executed the test problems included in this package on a CDC CYBER 740 computer. The following CPU times were required: 91.1 seconds (UNC32); 128.5 seconds (UNC33).

The programs UNC32/33 are relatively small programs which make the cross-section uncertainty data available for calculations with neutron spectrum adjustment codes and/or for the calculation of the uncertainty in calculated reaction rates.